In connection with certain services provided by our payroll operations, we collect funds from our clients’ accounts in advance of paying client obligations. These funds held for clients are segregated and invested in accordance with our investment policy, which requires all investments carry an investment grade rating at the time of initial investment. These investments, primarily consisting of corporate and municipal bonds and US treasury bills, are classified as available-for-sale and are included in the “Funds held for clients” line item on the accompanying Consolidated Balance Sheets. The par value of these investments totaled $59.1 million and $55.7 million at September 30, 2019 and December 31, 2018, respectively, and had maturity or callable dates ranging from October 2019 through February 2024. The following table summarizes activities related to these investments for the nine months ended September 30, 2019 and the twelve months ended December 31, 2018 (in thousands):

	Nine Months Ended			Twelve Months Ended
	September 30, 2019			December 31, 2018
Fair value at beginning of period	$	56,556		$	51,101
Purchases		21,171			18,426
Redemptions		(311	)		(1,793	)
Maturities		(17,447	)		(10,445	)
Decrease in bond premium		(390	)		(377	)
Fair market value adjustment		1,243			(356	)
Fair value at end of period	$	60,822		$	56,556

In addition to the available-for-sale securities discussed above, we also hold certified deposits and other depository assets in the amount of $2.3 million and $2.3 million at September 30, 2019 and December 31, 2018, respectively, related to the funds held for clients.

We do not purchase or hold any derivative instruments for trading or speculative purposes. We utilize interest rate swaps to manage interest rate risk exposure associated with our floating-rate debt under the credit facility. Under these interest rate swap contracts, we receive cash flows from counterparties at variable rates based on the LIBOR and pay the counterparties a fixed rate. Refer to the Annual Report on Form 10-K for the year ended December 31, 2018 for further discussion on our interest rate swaps.

The following table summarizes our outstanding interest rate swaps and their classification in the accompanying Consolidated Balance Sheets at September 30, 2019 and December 31, 2018 (in thousands):

	September 30, 2019
	Notional		Fair
	Amount		Value		Balance Sheet Location
Interest rate swaps	$	70,000	$	(688)	Other non-current liability

	December 31, 2018
	Notional		Fair
	Amount		Value		Balance Sheet Location
Interest rate swaps	$	70,000	$	1,096	Other non-current assets

Under the terms of the interest rate swaps, we pay interest at a fixed rate of interest plus applicable margin as stated in the agreement, and receive interest that varies with the one-month LIBOR. The notional value, fixed rate of interest and expiration date of each interest rate swap as of September 30, 2019 was (i) $25 million – 1.300% - October 2020, (ii) $10 million – 1.120% - February 2021, (iii) $20 million – 1.770% - May 2022 and (iv) $15 million – 2.640% - June 2023. Refer to Note 10. Fair Value Measurements, for additional disclosures regarding fair value measurements.

The following table summarizes the effects of the interest rate swaps on the accompanying Consolidated Statements of Comprehensive Income for the three and nine months ended September 30, 2019 and 2018 (in thousands):

	(Loss) Gain Recognized in AOCL, net of tax				(Loss) Reclassified from AOCL into Expense
	Three Months Ended				Three Months Ended
	September 30,				September 30,
	2019		2018		2019			2018
Interest rate swap	$	(194)	$	123	$	(98	)	$	(104	)

	Nine Months Ended				Nine Months Ended
	September 30,				September 30,
	2019		2018		2019			2018
Interest rate swap	$	(1,351)	$	749	$	(371	)	$	(229	)